×

Impedance analysis technique for frequency domain characterization of magnetoelastic sensor element by measuring steady-state vibration of element while undergoing constant sine-wave excitation

  • US 7,912,661 B2
  • Filed: 02/23/2007
  • Issued: 03/22/2011
  • Est. Priority Date: 03/31/2006
  • Status: Expired due to Fees
First Claim
Patent Images

1. Circuitry for characterizing a resonant behavior response of a magnetoelastic sensor element during exposure to an excitation field generated by an interrogation coil, the circuitry comprising:

  • (a) an excitation circuit for providing an AC excitation signal to the coil;

    (b) a receive circuit for measuring a steady state total sensor signal from the coil with the magnetoelastic sensor element positioned within the excitation field;

    (c) a phase detection circuit for detecting phase of said steady state total sensor signal so measured; and

    (d) a processing unit for determining;

    (i) a total measured impedance spectrum from said steady state total sensor signal so measured, and(ii) a plurality of magnitude values representing the real part of a reconstructed impedance spectrum characterizing the resonant behavior response of the sensor element, wherein(iii) said reconstructed impedance spectrum is calculated by subtracting an impedance generally attributable to the coil during said providing said AC excitation signal, from said steady state total measured impedance.

View all claims
  • 2 Assignments
Timeline View
Assignment View
    ×
    ×